205435642 has 4 divisors (see below), whose sum is σ = 308153466. Its totient is φ = 102717820.

The previous prime is 205435631. The next prime is 205435649. The reversal of 205435642 is 246534502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 205377561 + 58081 = 14331^2 + 241^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (205435649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51358909 + ... + 51358912.

Almost surely, 2^205435642 is an apocalyptic number.

205435642 is a deficient number, since it is larger than the sum of its proper divisors (102717824).

205435642 is a wasteful number, since it uses less digits than its factorization.

205435642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102717823.

The product of its (nonzero) digits is 28800, while the sum is 31.

The square root of 205435642 is about 14333.0262680287. The cubic root of 205435642 is about 590.0542342178.

The spelling of 205435642 in words is "two hundred five million, four hundred thirty-five thousand, six hundred forty-two".